<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<canvas id="jsi-flying-fish-container"></canvas>
	</body>
	<script src="../商城相关/js/jq.js"></script>
	<script>
		var RENDERER = {
			POINT_INTERVAL : 5,
			FISH_COUNT : 3,
			MAX_INTERVAL_COUNT : 50,
			INIT_HEIGHT_RATE : 0.5,
			THRESHOLD : 50,
			
			init : function(){
				this.setParameters();
				this.reconstructMethods();
				this.setup();
				this.bindEvent();
				this.render();
			},
			setParameters : function(){
				this.$window = $(window);
				this.$container = $('#jsi-flying-fish-container');
				this.$canvas = $('<canvas />');
				this.context = this.$canvas.appendTo(this.$container).get(0).getContext('2d');
				this.points = [];
				this.fishes = [];
				this.watchIds = [];
			},
			createSurfacePoints : function(){
				var count = Math.round(this.width / this.POINT_INTERVAL);
				this.pointInterval = this.width / (count - 1);
				this.points.push(new SURFACE_POINT(this, 0));
				
				for(var i = 1; i < count; i++){
					var point = new SURFACE_POINT(this, i * this.pointInterval),
						previous = this.points[i - 1];
						
					point.setPreviousPoint(previous);
					previous.setNextPoint(point);
					this.points.push(point);
				}
			},
			reconstructMethods : function(){
				this.watchWindowSize = this.watchWindowSize.bind(this);
				this.jdugeToStopResize = this.jdugeToStopResize.bind(this);
				this.startEpicenter = this.startEpicenter.bind(this);
				this.moveEpicenter = this.moveEpicenter.bind(this);
				this.reverseVertical = this.reverseVertical.bind(this);
				this.render = this.render.bind(this);
			},
			setup : function(){
				this.points.length = 0;
				this.fishes.length = 0;
				this.watchIds.length = 0;
				this.intervalCount = this.MAX_INTERVAL_COUNT;
				this.width = this.$container.width();
				this.height = this.$container.height();
				this.fishCount = this.FISH_COUNT * this.width / 500 * this.height / 500;
				this.$canvas.attr({width : this.width, height : this.height});
				this.reverse = false;
				
				this.fishes.push(new FISH(this));
				this.createSurfacePoints();
			},
			watchWindowSize : function(){
				this.clearTimer();
				this.tmpWidth = this.$window.width();
				this.tmpHeight = this.$window.height();
				this.watchIds.push(setTimeout(this.jdugeToStopResize, this.WATCH_INTERVAL));
			},
			clearTimer : function(){
				while(this.watchIds.length > 0){
					clearTimeout(this.watchIds.pop());
				}
			},
			jdugeToStopResize : function(){
				var width = this.$window.width(),
					height = this.$window.height(),
					stopped = (width == this.tmpWidth && height == this.tmpHeight);
					
				this.tmpWidth = width;
				this.tmpHeight = height;
				
				if(stopped){
					this.setup();
				}
			},
			bindEvent : function(){
				this.$window.on('resize', this.watchWindowSize);
				this.$container.on('mouseenter', this.startEpicenter);
				this.$container.on('mousemove', this.moveEpicenter);
				this.$container.on('click', this.reverseVertical);
			},
			getAxis : function(event){
				var offset = this.$container.offset();
				
				return {
					x : event.clientX - offset.left + this.$window.scrollLeft(),
					y : event.clientY - offset.top + this.$window.scrollTop()
				};
			},
			startEpicenter : function(event){
				this.axis = this.getAxis(event);
			},
			moveEpicenter : function(event){
				var axis = this.getAxis(event);
				
				if(!this.axis){
					this.axis = axis;
				}
				this.generateEpicenter(axis.x, axis.y, axis.y - this.axis.y);
				this.axis = axis;
			},
			generateEpicenter : function(x, y, velocity){
				if(y < this.height / 2 - this.THRESHOLD || y > this.height / 2 + this.THRESHOLD){
					return;
				}
				var index = Math.round(x / this.pointInterval);
				
				if(index < 0 || index >= this.points.length){
					return;
				}
				this.points[index].interfere(y, velocity);
			},
			reverseVertical : function(){
				this.reverse = !this.reverse;
				
				for(var i = 0, count = this.fishes.length; i < count; i++){
					this.fishes[i].reverseVertical();
				}
			},
			controlStatus : function(){
				for(var i = 0, count = this.points.length; i < count; i++){
					this.points[i].updateSelf();
				}
				for(var i = 0, count = this.points.length; i < count; i++){
					this.points[i].updateNeighbors();
				}
				if(this.fishes.length < this.fishCount){
					if(--this.intervalCount == 0){
						this.intervalCount = this.MAX_INTERVAL_COUNT;
						this.fishes.push(new FISH(this));
					}
				}
			},
			render : function(){
				requestAnimationFrame(this.render);
				this.controlStatus();
				this.context.clearRect(0, 0, this.width, this.height);
				this.context.fillStyle = 'hsl(0, 0%, 95%)';
				
				for(var i = 0, count = this.fishes.length; i < count; i++){
					this.fishes[i].render(this.context);
				}
				this.context.save();
				this.context.globalCompositeOperation = 'xor';
				this.context.beginPath();
				this.context.moveTo(0, this.reverse ? 0 : this.height);
				
				for(var i = 0, count = this.points.length; i < count; i++){
					this.points[i].render(this.context);
				}
				this.context.lineTo(this.width, this.reverse ? 0 : this.height);
				this.context.closePath();
				this.context.fill();
				this.context.restore();
			}
		};
		var SURFACE_POINT = function(renderer, x){
			this.renderer = renderer;
			this.x = x;
			this.init();
		};
		SURFACE_POINT.prototype = {
			SPRING_CONSTANT : 0.03,
			SPRING_FRICTION : 0.9,
			WAVE_SPREAD : 0.3,
			ACCELARATION_RATE : 0.01,
			
			init : function(){
				this.initHeight = this.renderer.height * this.renderer.INIT_HEIGHT_RATE;
				this.height = this.initHeight;
				this.fy = 0;
				this.force = {previous : 0, next : 0};
			},
			setPreviousPoint : function(previous){
				this.previous = previous;
			},
			setNextPoint : function(next){
				this.next = next;
			},
			interfere : function(y, velocity){
				this.fy = this.renderer.height * this.ACCELARATION_RATE * ((this.renderer.height - this.height - y) >= 0 ? -1 : 1) * Math.abs(velocity);
			},
			updateSelf : function(){
				this.fy += this.SPRING_CONSTANT * (this.initHeight - this.height);
				this.fy *= this.SPRING_FRICTION;
				this.height += this.fy;
			},
			updateNeighbors : function(){
				if(this.previous){
					this.force.previous = this.WAVE_SPREAD * (this.height - this.previous.height);
				}
				if(this.next){
					this.force.next = this.WAVE_SPREAD * (this.height - this.next.height);
				}
			},
			render : function(context){
				if(this.previous){
					this.previous.height += this.force.previous;
					this.previous.fy += this.force.previous;
				}
				if(this.next){
					this.next.height += this.force.next;
					this.next.fy += this.force.next;
				}
				context.lineTo(this.x, this.renderer.height - this.height);
			}
		};
		var FISH = function(renderer){
			this.renderer = renderer;
			this.init();
		};
		FISH.prototype = {
			GRAVITY : 0.4,
			
			init : function(){
				this.direction = Math.random() < 0.5;
				this.x = this.direction ? (this.renderer.width + this.renderer.THRESHOLD) : -this.renderer.THRESHOLD;
				this.previousY = this.y;
				this.vx = this.getRandomValue(4, 10) * (this.direction ? -1 : 1);
				
				if(this.renderer.reverse){
					this.y = this.getRandomValue(this.renderer.height * 1 / 10, this.renderer.height * 4 / 10);
					this.vy = this.getRandomValue(2, 5);
					this.ay = this.getRandomValue(0.05, 0.2);
				}else{
					this.y = this.getRandomValue(this.renderer.height * 6 / 10, this.renderer.height * 9 / 10);
					this.vy = this.getRandomValue(-5, -2);
					this.ay = this.getRandomValue(-0.2, -0.05);
				}
				this.isOut = false;
				this.theta = 0;
				this.phi = 0;
			},
			getRandomValue : function(min, max){
				return min + (max - min) * Math.random();
			},
			reverseVertical : function(){
				this.isOut = !this.isOut;
				this.ay *= -1;
			},
			controlStatus : function(context){
				this.previousY = this.y;
				this.x += this.vx;
				this.y += this.vy;
				this.vy += this.ay;
				
				if(this.renderer.reverse){
					if(this.y > this.renderer.height * this.renderer.INIT_HEIGHT_RATE){
						this.vy -= this.GRAVITY;
						this.isOut = true;
					}else{
						if(this.isOut){
							this.ay = this.getRandomValue(0.05, 0.2);
						}
						this.isOut = false;
					}
				}else{
					if(this.y < this.renderer.height * this.renderer.INIT_HEIGHT_RATE){
						this.vy += this.GRAVITY;
						this.isOut = true;
					}else{
						if(this.isOut){
							this.ay = this.getRandomValue(-0.2, -0.05);
						}
						this.isOut = false;
					}
				}
				if(!this.isOut){
					this.theta += Math.PI / 20;
					this.theta %= Math.PI * 2;
					this.phi += Math.PI / 30;
					this.phi %= Math.PI * 2;
				}
				this.renderer.generateEpicenter(this.x + (this.direction ? -1 : 1) * this.renderer.THRESHOLD, this.y, this.y - this.previousY);
				
				if(this.vx > 0 && this.x > this.renderer.width + this.renderer.THRESHOLD || this.vx < 0 && this.x < -this.renderer.THRESHOLD){
					this.init();
				}
			},
			render : function(context){
				context.save();
				context.translate(this.x, this.y);
				context.rotate(Math.PI + Math.atan2(this.vy, this.vx));
				context.scale(1, this.direction ? 1 : -1);
				context.beginPath();
				context.moveTo(-30, 0);
				context.bezierCurveTo(-20, 15, 15, 10, 40, 0);
				context.bezierCurveTo(15, -10, -20, -15, -30, 0);
				context.fill();
				
				context.save();
				context.translate(40, 0);
				context.scale(0.9 + 0.2 * Math.sin(this.theta), 1);
				context.beginPath();
				context.moveTo(0, 0);
				context.quadraticCurveTo(5, 10, 20, 8);
				context.quadraticCurveTo(12, 5, 10, 0);
				context.quadraticCurveTo(12, -5, 20, -8);
				context.quadraticCurveTo(5, -10, 0, 0);
				context.fill();
				context.restore();
				
				context.save();
				context.translate(-3, 0);
				context.rotate((Math.PI / 3 + Math.PI / 10 * Math.sin(this.phi)) * (this.renderer.reverse ? -1 : 1));
				
				context.beginPath();
				
				if(this.renderer.reverse){
					context.moveTo(5, 0);
					context.bezierCurveTo(10, 10, 10, 30, 0, 40);
					context.bezierCurveTo(-12, 25, -8, 10, 0, 0);
				}else{
					context.moveTo(-5, 0);
					context.bezierCurveTo(-10, -10, -10, -30, 0, -40);
					context.bezierCurveTo(12, -25, 8, -10, 0, 0);
				}
				context.closePath();
				context.fill();
				context.restore();
				context.restore();
				this.controlStatus(context);
			}
		};
		$(function(){
			RENDERER.init();
		});
	</script>
</html>
